Relationships between Medication Adherence and Cardiovascular Disease Risk Factor Control in Elderly Patients with Diabetes.

Abstract

The Centers for Medicare and Medicaid Services (CMS) Medicare Star program provides incentives to health plans when their patients with diabetes meet adherence targets to angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEIs/ARBs) and statins. While a link between adherence and cardiovascular risk factor control is established, most studies included young patients with few comorbidities. Whether the Star adherence target is associated with reduced blood pressure or low-density lipoprotein cholesterol (LDL-C) in complex older patients is not well understood. Determine correlates of adherence and examine the effect of meeting Star adherence targets on blood pressure and LDL-C in the Medicare-aged diabetes population. Retrospective cohort study of 129,040 patients with diabetes aged 65 or older. Adherence estimated using proportion of days covered target ≥ 0.8; blood pressure < 140/90 mg Hg; LDL-C < 100 mg/dl. Modified Poisson regression used to assess relationships. Adherence differed little across elderly age groups. Compared to no comorbidity, high comorbidity (≥ 4) was associated with lower ACEI/ARB (risk ratio [RR] 0.88 [95% confidence interval (CI) 0.87-0.89]) or statin (RR 0.91 [0.90-0.92]) adherence. ACEI/ARB adherence was not associated with blood pressure < 140/90 mm Hg in patients ≥ 85 years (RR 1.01 [0.96-1.07]) or with multiple comorbidities (e.g., 3: RR 1.04 [0.99-1.08]). Statin adherence and LDL-C < 100 mg/dl were associated in all elderly age groups (e.g., ≥ 85: RR 1.13 [1.09-1.16]) and comorbidity levels (e.g., ≥ 4: RR 1.13 [1.12-1.15]). Adherence to ACEI/ARB is not linked with reduced blood pressure in patients with diabetes who are at least 85 years or with multiple comorbidities.